Electrical cables are commonly used to transmit analog signals and digital data. These cables often include a pre-twisted pair of wires to improve electrical and mechanical properties. These pre-twisted wires are cabled or paired together in a cabling device at typically high speeds which impart significant forces, e.g, tension, to the wires often deforming them.
Industry specifications dictating the strain on wires during cabling are stringent, e.g., the wire's conductor cannot be stretched more than 1/10,000 of an inch measured across the diameter. These specifications can result in a substantial amount of discarded wire.
U.S. Pat. No. 3,969,880 to Maillefer et al. describes a cabler that incorporates a capstan or pulling device inside of a rotating doubletwisting bow. The wire is twisted as the wire enters the bow, and then is fed down one side of the bow and twisted again at the other side of the bow after which the wire is taken up. At higher speeds, the capstan must pull the wire with higher tensile forces due to the frictional forces acting on the wire through the bow. This often pulls the wire out of specification.
Another prior art system avoids using a capstan and pulls the wire through the bow using the take-up reel. This system suffers from the same deficiency in that the wire is pulled through the bow with increased tension as the rotational speed of the bow increases often resulting in damaged wire.